Bulk redirect imports can fail in WordPress even when the redirect list itself is valid. In one post-launch troubleshooting case, importing a redirect spreadsheet with 301 Redirects Pro caused an infinite redirect loop on the homepage, while the same redirect data worked correctly on staging with the Redirection plugin.
The investigation showed that the problem was not simply a malformed list. Instead, 301 Redirects Pro had stricter import-format requirements and skipped a number of entries without providing detailed explanations. Some redirect types, including certain .pdf to .pdf redirects, could be added manually but did not import successfully in bulk.
Issue background
A recently launched WordPress site needed a large redirect list imported so old URLs would continue sending visitors and search engines to the correct new locations.
When the redirect list was uploaded through 301 Redirects Pro, the homepage entered an infinite redirect loop. Because the issue appeared immediately after the import, the first suspicion was that one or more rows in the redirect spreadsheet were malformed.
As an initial test, rows containing asterisks were removed and a simplified version of the list was imported into a staging site using the Redirection plugin. That version worked correctly. The original redirect list was then tested on staging with Redirection as well, and it also worked.
That comparison pointed away from the list itself and toward plugin-specific import behavior.
Diagnosis
The developer reviewed the format expected by 301 Redirects Pro and determined that the original spreadsheet was not in the format the plugin expected for bulk import.
A new version of the list was created in a format intended to be compatible with 301 Redirects Pro. Even then, many entries were skipped during import without a detailed explanation from the plugin.
One specific limitation encountered during testing involved redirects from one PDF URL to another PDF URL. Those redirects could be added manually, but the developer was unable to get them to import successfully through the plugin’s bulk-import process.
At the same time, the same redirect data continued to work with the Redirection plugin on staging. This made the plugin choice an important part of the diagnosis: redirect behavior that works in one WordPress redirect plugin may not import cleanly into another because of different CSV formats, parsing rules, wildcard handling, or supported redirect patterns.
Resolution steps
A practical workflow for troubleshooting this type of redirect import problem is:
- Test the redirect list on staging first. Import the same data into a safe environment before repeatedly changing redirects on production.
- Separate list problems from plugin problems. If the same redirects work correctly in another established plugin such as Redirection, the data may be valid even if the original plugin rejects it.
- Check the exact import format required by the plugin. Redirect plugins do not all use the same CSV structure. Reformat the source and destination columns to match the plugin’s documented importer.
- Watch for silently skipped entries. A bulk import can appear successful while leaving out some redirects. Compare the imported count with the source list and spot-check representative entries.
- Test difficult redirect types individually. File-to-file redirects such as
.pdfto.pdf, wildcard-style patterns, and other nonstandard mappings may behave differently from simple one-to-one page redirects. - Add unsupported redirects manually where necessary. In this case, some redirects that could not be imported in bulk could still be created manually.
- Remove or deactivate redirects that should not remain active. After the main list was working, redirects pointing to outdated
/blog/...destinations were deactivated. - Add follow-up mappings separately. A second set of redirects that were not straightforward one-to-one matches was added after the primary import had been stabilized.
- Retest critical URLs. Confirm that the homepage no longer loops and that high-value old URLs resolve to the intended destinations.
The task also demonstrated the value of having a preferred redirect plugin available for testing. Redirection provided a useful control because it accepted the redirect data successfully on staging while 301 Redirects Pro continued to skip entries.
Final outcome
The redirect implementation was completed without changing the underlying redirect list wholesale. The client was ultimately able to import the main list, and the remaining cleanup was handled by deactivating unwanted /blog/... redirects and adding a separate set of additional mappings.
The most important lesson is that an infinite redirect loop after a bulk import does not automatically mean the spreadsheet is bad. Test the same mappings in staging, verify the target plugin’s required import format, compare imported and skipped entries, and be prepared to handle unsupported redirect patterns manually.
If you are dealing with redirect loops, skipped CSV imports, 301 Redirects Pro, Redirection, or a large WordPress migration with complex URL mappings, contact Freshy. Our WordPress team can help audit redirect lists, troubleshoot import compatibility, and verify that redirects are working correctly after launch.
